Manufacture of crepe yarns and fabrics



Feb. 13,1962 Q N'JKAMP 3,020,699

MANUFACTURE OF CREPE YARNS AND FABRICS Filed July 50, 1957 INVENTORSDERK JAN EVERHARD NIJKAMP GERRIT JAN VAN LOCHEM i JAN GRADUS vos BY MWNEY United States Patent 3,020,699 MANUFACTURE OF CREPE YARNS ANDFABRICS Derk Jan Everhard Nijkamp, Velp, and Gerrit Jan van Lochem andJan Gradus Vos, Arnhem, Netherlands, assignors, by mesne assignments, toE. I. du Pont de Nemours and Company, Wilmington, Del., a corporation ofDelaware Filed July 30, 1957, Ser. No. 674,996 Claims priority,application Netherlands Aug. 2, 1956 9 Claims. (Cl. 57-157) Thisinvention relates to the production of crepe yarns and creped fabricsmade therefrom.

It is, of course, well known that crepe fabric having a crinkled orpuckered effect may be produced by employing crepe yarns having a veryhigh or hard twist. The crepe fabric may contain crepe yarns in the warpor weft, or both. When the fabric is wet out for the first time afterweaving in the creping process which precedes dyeing and finishing, thecrepe yarns crinkle and shrink against the resistance offered by thenon-crepe yarns. Creping produces a fabric having attractive surfacedesigns. However, the fibers or filaments in a crepe yarn must be veryclosely bound together in view of the fact that the primary function ofthe high twist in crepe yarns is to produce such a compact thread thatthe fibers or filaments have very little lateral freedom of movement.Accordingly, the softness of hand and covering power may not be entirelysatisfactory, especially when continuous filaments are used.

A method of producing a bulky yarn is disclosed in copending applicationSerial No. 354,503, filed May 12, 1953, now US. Patent 2,874,443, havingcommon ownership with the present application. This yarn possesses thecombined properties of a filament yarn and a spun yarn and has thebulkiness and covering power of a spun yarn, the evenness of a filamentyarn and its own particular structure and hand. This yarn in particularis characterized by filaments that are individually convoluted intocoils, loops and whorls at random intervals along their lengths.

The principle underlying the manufacture of the above describedvoluminous or bulky yarn is the displacement of the filaments in astrong current of air, as the result of which loops or filaments projectoutwardly from the body of the threads. Ordinarily, this operationshortens the thread, thus increasing the filament count and the volume.

The loops in the filaments impart several characteristic properties tothis yarn. The normal properties of the yarn are not fundamentallyaltered by this blowing process. It does, however, acquire several newproperties, in addition to those already mentioned, such as greaterinsulating power, enhanced capacity to absorb moisture, a toned-downluster, and others. However, fabric made from the looped yarns oftenhave the disadvantage of creasing during use.

An object of the present invention is to provide a method for producingcrepe continuous multifilament yarn having many of the apparentcharacteristics of wool, such as softness of feel, warmth and bulk.

Another object of the present invention is to provide a crepe yarnhaving the aforesaid desirable properties.

An additional object of the present invention is to provide a crepetextile fabric resembling fine woolen crepe fabrics.

Other objects will become apparent from the following description.

In the drawing, FIGURE 1 represents a diagrammatic enlarged top view ofa fabric made according to the present invention. FIGURE 2 represents adiagrammatic cross section along the line 2-2 of FIGURE 1.

In accordance with the present invention, two or more ends of continuousmultifilament threads having different shrinkage characteristics areplied together to form a crepe twist yarn. The filaments of the yarn,either before or after plying, are displaced by the action of astrongcurrent of air thereon; and as a result thereof, random filamentaryloops project outward-1y from the yarn. The yarn thus formed isprocessed into crepe fabric. Very surprisingly, it has been found thatthis crepe fabric is highly crease resistant during use. I

According to a preferred embodiment of the present invention, a fullyshrunk nylon thread is combined with an unshrunk nylon thread afterwhich the yarn is processed to the crepe fabric with this invention. Afully shrunk nylon thread as used herein is one which upon immersing inboiling water will not shrink more than 3% and-preferably less than /2%.

may be fully shrunk, for example, by subjecting it in cake form to theaction of live steam at C. for about atwo-hour period. Also,polycaprolactam yarn and poly (hexamethyleneadipamide) yarn are verysuitable compo nents when used together in view of their inherentlydifferent shrinkages.

Crepe fabric made entirely of nylon yarn has the im proved properties asherein described. This was unexpected since nylon does not crepe easilyand was not heretofore regarded as -a suitable material for producingcrepe fabric.

The present invention contemplates, in general, processing differentcontinuous multifilament threads into what is essentially a blendedfilament creye yarn having a bulky structure and possessing randomfilamentary loops. The.

process may be carried out in accordance with various favorablemodifications. The threads may be first combined and thereafter bulked;or part of the component threads may be bulked and thereafter combined.

According to the first modification the threads to be plied togethermaybe twisted or not twisted. However,

are plied together with a high crepe twist in the range of 300 to 1000turns per meter. The composite yarn preferably has a twist'of from 500to 700 turns per meter.

By having such a high twist. the yarn when released from tension has atendency to form kinks; and conse-. quently, difficulties may arise whensubjecting this twistlivelv varn to the action of the air. Accordingly,before the blowing process this twisted yarn may be treated to reduceits twist-liveliness. In order to do this, t e yarn may be treated withany suitable agent for accomplishing this. However, preferably thetwist-liveliness is reduced by treating it with an oil or oil emulsionwhich also imparts antistatic properties to the yarn. This can beaccomplished by using any suitable sizing system.

After the threads are twisted together, the composite yarn is fed to abulking jet of the tvpe disclosed in copending application Serial No.410,918, filed February 17, 1954, now US. Patent 2,874,444 having commonownership herewith. The yarn enters the jet at an angle. Air underpressure propels the yarn through a confined zone in the jet. Shortlyafter leaving the jet the direction of yarn travel is changed while theyarn is still under the influence of the stream of air. The change indirection may be accomplished by having the yarn impinge against anobstacle after leaving the jet. Thereafter the yarn is taken up in anorderly arrangement in a package form.

An unshrunk nylon thread has a' residual shrinkage in the range of11-13%. Nylon thread" According to the second modification, part of thethreads having different shrinkage properties is bulked as abovedescribed prior to being plied together with an unbulked portion. Thethreads may be twisted or nontwisted; but preferably they are twisted.However, if only one component is twisted, then, of course, it ispreferred t9 bulk this thread. Moreover, if all of the component threadsare twisted, it is preferred that the direction of twist be the same forall the threads. It is not necessary that the threads have the samenumber of turns per given length. Furthermore, the plying of the threadsis preferably accomplished in a direction opposite to the direction oftwist in the threads. It is best that the composite yarn have a twist ofabout 100 to 500 turns per meter.

It is preferred, according to the second modification of the presentinvention, to bulk the thread with a jet adapted in such a manner thatthe air in the jet is given a helical rngvernent running in the samedirection as the twist in the thread. A jet of this type is disclosed incopending application Serial No. 484,218, filed January 26, 1955, nowUS. Patent 2,924,000, owned by the present assignee. The windingvelocity of the bulked thread is preferably at least 5% less than thevelocity with which the thread is delivered to the bulking jet In somecases it may be preferred to reduce the twist liveliness of thecomposite yarn which may be accomplished as hereinabove described.

The bulked yarn may. now be woven to produce the crepe fabric of thepresent invention. The said fabric may contain the yarn in the warp. orweft, or both. The creping power of these new yarns is so satisfactorythat they may be woven into a large variety of weaves depending upon thetype of crepe desired. For example, a very od. r pe f b i m b wove t theyarns e the present invention, alternately with a yarn of right hand w san h yarn o eft he d tw st- After the wearing of the yarn into asuitable fabric, h er hlsl ns e p ble e tee h racter sti c p fehrie y hemparted i seve a i fer n w s r e a y. h is. enehy mmersing t fa ri i a,en o r e h n. n a at at h t wa r r se n solut on fo e b eng h Qt ime Thehath is pre err d t be m i tained at a temperature of fron 95 tq 100 C.After ith w g the rn r m the hath a d. rinsin i essary, the crepe fabricis dried tension-tree or nnder some tension.

The invention is generally applicable to the use of any two or moretypes of yarn, 'the only requirements being t the empb e arn ha e di ire tt shri k properties and the 'twist as herein described. Thecomposite yarn of the present invention may h composed entirely of onetype qf fiber. However, the shrinkage extent of one component must hemore or less than the other. Also, it is not necessary that the threadsconsist of the same material. Thus, for example, threads of polyamideand polyacrylonitrile, cellulose acetate and viscose, polyamide andpolyvinyichloride, etc., may be twisted together provided that thethreads have different shrinkage properties.

If the yarn consists of thermoplastic; filaments the crepe fabric shouldbe dried frce of tension. In addition, the fabric with or withouttension should then be stabilized by adrying operation, both in thedirection of the width and the length, and at high temperatures at leasthigher than those used during washing, This maybe accomp in a aqwn h heThe fab c a he y and otherwise handled as any crepe fabric.

e crehe f r e P edneed in eeeerdanee th t pr sent i v nt n h ma y ee tehe r p t e t has a Well fi her etea e t l eh f'h hd d a Well n s t or s iht w t. nd s hi hl etea resistant- Also, the crepe effect issubstantially permanent under orm l dl r 9 use. n uses areundergarments, bl us s dre ses eeeess ie i linings,

A crepe fabric ofthe present invention is particularly characterized bybeing produced at least in part from a twist-lively yarn having randomfilamentary loops projecting outwardly therefrom to provide a markedinterfilament friction. The yarn is composed of at least two continuousmultifilament threads twisted together and possessing differentshrinkage characteristics. The loops are formed by the action of astrong current of air on the yarn. The fabric is creped due to thedifferential shrinkage between the threads upon treating the fabric in ahot liquid.

For a fuller understanding of the invention, reference is made to thefollowing examples which are given merely to further illustrate theinvention and are not to be con strued in a limiting sense.

Example I An unshrunk 50 denier/ 10 filament polycaprolactam nylonthread having a low S-twist of 20 turns per meter was plied togetherwith a fully shrunk 70 denier/24 filament polycaprolactam nylon threadalso having a low S-twist of 20 turns per meter to form a composite yarnhaving an S-twist of 600 turns per meter.

The plied yarn thus obtained was propelled through a tube by means of afiow of gas in the manner described in application Serial No. 354,503referred to above. After leaving the tube the direction of movement ofthe yarn was changed; and the yarn was wound on a take-up device. Thewinding velocity of the looped yarn was 20% lower than the velocity withwhich the plied yarn was drawn off a spool.

A looped yarn having an original Z-twist of 600 turns per meter wasmanufactured in the same manner.

The S-twist and Z-twist yarns were woven alternately as the weft of afabric. The warp consisted of normal smooth 50 denier/10 filamentpolycaprolactam nylon} threads.

The fabric was washed over its entire width at C. in a tension-freecondition and then dried without tension. Finally, the fabric wasstabilized under a slight tension at C. The finished fabric had a crepeappearance resembling fine woolen crepe fabric. Upon dyeing and repeatedwashing, the crepe structure remained substantially unchanged.

Example II A completely shrunk 72 denier/ 38 filament polycaprolactamnylon thread having an S-twist of 800 turns per meter was bulked bypropelling it through a tube by means of a flow of gas in the mannerdescribed in application Serial No. 354,503, referred to above. Afterleaving the tube the direction of movement of the yarn was changed; andthe yarn was wound on a take-up device. The winding velocity of thelooped yarn was 15% lower thanlthe velocity with which the yarn wasdrawn olf a spoo The looped yarn thus obtained was plied with anunshrunk and unbulked 72 denier/ 24 filament polycaprolactam nylonthread having an S-twist of 300 turns per meter to form a composite yarnhaving a Z-twist of 200 turns per meter.

This composite yarn was woven as the weft of a fabric.

The warp consisted of normal smooth 72 denier/24 filamentpolycaprolactam nylon threads.

The fabric was washed over its entire width at 95 C. in a tension-freecondition and then dried without ten sion. Finally, the fabric wasstabilized under a slight tension at 190 C. The finished fabric had acrepe appearance resembling fine woolen crepe fabric. Upon dyeing andrepeated washing, the crepe structure remained substantially unchanged.

Certain modifications and equivalents of the present invention willbecome apparent to those skilled in the art and are intended to beincluded within the scope of the present invention, which is to belimited only to the ex tent of the appended claims. a i i What isclaimed is:

l. A method of producing yarn suitable for crepe fabric which comprisestwisting together at least two continuous multifilament threads having alow twist and different shrinkage properties into a twist-livelycomposite yarn, displacing the filaments of the composite yarn by theaction of a strong current of air as the result of which randomfilamentary loops project outwardly therefrom subjecting the compositeyarn to a shrinkinginducing temperature and collecting the yarn in anorderly manner.

2. A method of producing yarn suitable for crepe fabric which comprisestwisting together at least two continuous multifilament nylon threadshaving different shrinkage properties into a twist-lively yarn,displacing the filaments of the composite yarn by the action of a strongcurrent of air as the result of which random filamentary loops projectoutwardly therefrom subjecting the composite yarn to ashrinkage-inducing temperature and collecting the yarn in an orderlymanner.

3. A method of producing yarn suitable for crepe fabric which comprisestwisting together two continuous multifilament nylon threads having atwist of less than 150 turns per meter and different shrinkageproperties into a twist-lively composite yarn, displacing the filamentsof the composite yarn by the action of a strong current of air as theresult of which random filamentary loops project outwardly therefromsubjecting the composite yarn to a shrinkage-inducing temperature andcollecting the yarn in an orderly manner.

4. A method of producing yarn suitable for crepe fabric which comprisestwisting together at least two continuous multifilament nylon threadshaving a twist of less than 150 turns per meter and different shrinkageproperties into a composite yarn having a twist of from 300 to 1000turns per meter, displacing the filaments of the composite yarn by theaction of a strong current of air as the result of which randomfilamentary loops project outwardly therefrom subjecting the compositeyarn to a shrinkage-inducing temperature and collecting the yarn in anorderly manner.

5. A method of producing yarn suitable for crepe fabric which comprisesdisplacing the filaments of a first continuous multifilament thread bythe action of a strong current of air as the result of which randomfilamentary loops project outwardly therefrom, twisting said threadtogether with a second continuous multifilament thread having differentshrinkage. properties as compared with said first thread into acomposite yarn subjecting the composite yarn to a shrinkage-inducingtemperature and thereafter collecting the yarn.

6. A method of producing yarn suitable for crepe fabric which comprisesdisplacing the filaments of a first continuous multifilament nylonthread by the action of a strong current of air as the result of whichrandom filamentary loops project outwardly therefrom, twisting saidthread together with a second continuous multifilament yarn havingrandom filamentary coils, loops and whorls V projecting outwardlytherefrom and plied from at least two continuous multifilament threadshaving different shrinkage properties.

9. A crepe fabric containing a weft of a twist-lively yarn having randomfilamentary coils, loops and whorls projecting outwardly therefrom andplied from two continuous multifilament nylon threads having differentshrinkage properties.

References Cited in the file of this patent UNITED STATES PATENTS2,504,523 Harris et al Apr. 18, 1950 2,575,753 Foster Nov. 20, 19512,656,585 Jackson Oct. 27, 1953 2,783,609 Breen Mar. 5, 1957 2,789,340Cresswell Apr. 23, 1957 2,852,906

Breen Sept. 23, 1958

4. A METHOD OF PRODUCING YARN SUITABLE FOR CREPE FABRIC WHICH COMPRISESTWISTING TOGETHER AT LEAST TWO CONTINUOUS MULTIFILAMENT NYLON THREADSHAVING A TWIST OF LESS THAN 150 TURNS PER METER AND DIFFERENT SHRINKAGEPROPERTIES INTO A COMPOSITE YARN HAVING A TWIST OF FROM 300 TO 1000TURNS PER METER, DISPLACING THE FILAMENTS OF THE COM-